National-populist parties display a discourse based on the defense of the national integrity. However, in the current European context, these parties have to deal with an increasing cultural heterogeneity, new forms of citizenship, and multi-scaling arenas. How does national-populism develop its narratives in these settings? The paper elaborates a framework for understanding the way in which ambiguity is included in the discursive strategies of national-populists. Through the Critical Discourse Analysis approach, the contribution will focus on the analysis of the discourses produced by three parties located at the Swiss-Italian border at the time of the referendum campaign for the 2014 Swiss initiative “Against Mass Immigration.”